Mp3 Player Purchase Tips

Mp3 Player Purchase Tips
by: Roberto Sedycias

The idea of a having a portable audio player dates back many years ago, when the option then was a fairly big cassette-tape-playing two-speaker audio system. Eventually these devices got smaller and back in the late seventies a hand size cassette-tape audio player was made available. Now as electronics evolved and with the mp3 audio format, one can satisfy his needs for a portable audio device thru the use of mp3 players.

Mp3 players became very popular and it is very common to see people using it while doing many activities such as jogging, commuting to work, traveling, buying groceries, computer related tasks and others.

For those who intend to purchase an mp3 player, one might consider the following tips:

1 - The internal memory size of an mp3 player will determine the amount of mp3 songs the device will be able to hold. Some models may even have an internal hard drive to store songs, however the size and price may go up a little bit and it is not recommend to be used by someone doing intensive physical activities. Also some models may the have the option of flash memory.

2 - The battery life is a very important feature, because it will determine how many hours the mp3 player will function properly. Make sure the mp3 player comes with an AC/DV adapter for quick battery charge.

3 - There a lots of sizes of mp3 players. Features such as a larger screen, video capability, hard drive and others, all add up to a bigger size. And price too!

4 - The way an mp3 player connects to a computer is a also very important feature. Latest model may support high speed USB 2.0 transfer. Some others may even have Firewire support.

5 - Some mp3 players even may accept other audio format besides mp3, such as WMA format. Check the player’s specification if this feature is going to be used.

6 - Also mp3 players may have other features besides of mp3 playing. Features such as FM tuner and audio recording capability, may be of some interest to some users.

7 - As for the price just make sure the mp3 player you are buying has just the features you are looking for. Why pay more for features you are not going to be using anyway? Mp3 players can be purchased for prices from fifty up to several hundred dollars. Brand name players will cost even more.

Portable mp3 players have become a must have product of desire among the younger population. After all almost everyone has one of them. So if you don’ have one yet, it’s about time to keep yourself updated with modern time.

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Interesting Facts About Cell Phones

Interesting Facts About Cell Phones
by: Roberto Sedycias

Cell phone (telefone celular) is a wireless, portable, long-range, electronic telephone, which during travel can seamlessly change antenna connections, from one radio reception cell to another radio reception cell, without dropping or losing the ongoing call.

Besides the standard voice function of a telephone, latest cell phones (telefone celular) have features such as SMS for text messages, MMS for multimedia messages, radio, games, internet connectivity for email, browsing, blogging, music (MP3) playback, memo recording, built-in cameras and camcorders, ringtones, personal organizers, Push-to-Talk (PTT), Bluetooth and infrared connectivity, call registers, streaming video, downloading video, video call, and also serve as wireless modems for PCs that can be connected to the Internet.

The power in a cell phone (telefone celular) is obtained from rechargeable batteries, which can be recharged from the mains, a USB port or a cigarette lighter port in an automobile. Nickel Metal Hydride were the most common types of batteries, which due to the "memory effect" (the user can recharge only when the entire battery is drained off) were replaced by Lithium-Ion batteries, which did not suffer from any memory effect.

Cell phones (telefone celular) came into existence because of the invention of hexagonal cells in 1947, for the base stations by Bell Labs engineers at AT&T. This was further developed during the 1960s by Bell Labs. During a call, the channel frequency could not be changed automatically from one cell (base station coverage area) to another cell (base station coverage area) as the person traveled from the area of one cell to the area of another cell. Amos Joel of Bell Labs invented a breakthrough invention and called it as the `call handoff` by which the channel frequency could be changed automatically from one cell to another cell, during the same call, as the mobile user traveled from one cell to another cell. Due to their heavy construction, these phones were used mainly in automobiles.

The first practical cell phone in a non-vehicle setting, and which could be handheld, was invented by Martin Cooper, the General Manager (Communications Division) of Motorola, who made the world`s first handheld cell phone (telefone celular) call on April 3, 1973.

The technology by which the cell phone (telefone celular) works depends on the mobile phone operator; however, all of them use electromagnetic radio waves, which are in touch with a cell site (base station). The base station is composed of several antennas which are mounted on a pole, tower, or building. Cell sites are spread at a distance of 5 to 8 miles (approx. 8 to 13 km) from each other. The low power transceiver from the cell phone transmits the voice and data to the nearest cell site. During movement, the cell phone will "handoff" the information to other cell site. Mobile phone operators use many technologies to maintain the smooth stream of digitized data from the cell phone to the cell site and vice versa.

The wireless telephone technologies are grouped under heads known as generations, starting from zero generation or 0G. The current generation going on is 4G; however, there are old cell phones (telefone celular) that still operate on 1G, 2G, and 3G technologies. The wireless telephone technologies used in each generation are as given below:

0G: PTT, MTS, IMTS, AMTS, OLT, MTD, Autotel/PALM, ARP

1G: NMT, AMPS/TACS/ETACS, Hicap, CDPD, Mobitex, DataTac

2G: GSM, iDEN, D-AMPS, IS-95/cdmaOne, PDC, CSD, PHS, GPRS, HSCSD, WiDEN, CDMA2000 1xRTT/IS-2000, EDGE (EGPRS)

3G: W-CDMA, UMTS (3GSM), FOMA, TD-CDMA/UMTS-TDD, 1xEV-DO/IS-856, TD-SCDMA, GAN (UMA), HSPA, HSDPA, HSUPA, HSPA+, HSOPA

4G : UMB, UMTS Revision 8 (LTE), WiMAX

Frequency bands: SMR, Cellular, PCS

The impact of cell phone (telefone celular) usage on human health has been of considerable worldwide concern. Research studies in Copenhagen, from the Danish Institute of Cancer Epidemiology, the National Cancer Institute, and the Institute of Cancer Research, do not establish any link between cancer and cell phone usage. However, an intergovernmental agency IARC (International Agency for Research on Cancer) forming part of the World Health Organization of the United Nations, undertook a study of 4,500 users and found a statistically significant link between cell phone usage and tumor frequency. Further research is going on.

Cell phone (telefone celular) usage and driving is a common worldwide phenomenon. Some jurisdictions have banned usage of hand-held phones during driving, but allowed the hands-free fashion of cell phone usage while driving. However, studies have found out that the distraction is caused by the conversation itself; hence, both hand-held and hands-free cell phones contribute towards road traffic accidents. Further studies on cell phone usage and driving are going on.

Nokia Corporation is currently the world`s largest manufacturer of cell phones (telefone celular). Other notable cell phone manufacturers, in alphabetical order, are 3G, Audiovox (now UT Starcom), Benefon, BenQ-Siemens, Fujitsu, High Tech Computer Corporation (HTC), Kyocera, LG Mobile, Motorola, NEC, Panasonic (Matsushita Electric), Pantech Curitel, Philips, Research In Motion, Sagem, Samsung, Sanyo, Sharp, Siemens, Sierra Wireless, SK Teletech, Sony Ericsson, T&A Alcatel, Toshiba, and Verizon.